The present invention relates generally to making up and breaking out wellbore tubulars and, more particularly, to apparatus and methods for a simplified self-contained power tong for use in a rig floor environment.
Power tong systems maybe used to spin, makeup, or connect and breakout or disconnect wellbore tubulars that may have a wide range of diameters. Comparison studies between use of traditional separate tongs and spinners as compared with a self-contained power tong system makeup and breakout tool working under similar conditions have shown cost savings that range from one-quarter of a million to more than a million dollars per well, depending on the well conditions.
Separate, manually operated tongs, spinners, and/or chains are significantly slower and less accurate and consistent in making up and breaking out wellbore tubulars than a single tool or unit that does all such functions. Besides increased speeds of making up and breaking out tubular connections, other time saving advantages of a self-contained power tong unit also include factors such as eliminating the need to redress tongs when changing from drill pipe to drill collars and the integration of spinning with makeup and breakout functions. Due to the high daily cost of drilling rigs, comparison studies show that the time/cost savings can be substantial.
The self-contained power tong system also operates more reliably than separate tongs and spinners and may provide a central torque regulator that connects to and controls all components to assure consistent makeup. This feature prevents thread damage caused by over-tightening and automatically prevents errors that could result in under-torqued connections. Obviously, a single error, when making up hundreds of threaded connections in a drill string, can result in huge costs of time and material, and even loss of a well.
The self-contained power tong system also eliminates accident conditions commonly associated with separately moveable independent tongs which apply high torque and which are located by personnel on the floor. As well, independent tongs have attendant separate cables used to pull on each separate tong, and may also use snatch blocks. Thus, the personnel must work between high tension cables that pull on the tongs and accidents can easily occur under such conditions, e.g., if a tong loses its grip and moves rapidly across the rig floor accelerated by the high tension on the cable. Of course, accidents can slow work progress and significantly increase the costs of drilling.
Safety is also improved because the invention provides a single tool to perform all such functions, rather than separate elements, permits the use of central safety features such as, for instance, a lockout to prevent spinner operation if the tongs are not engaged, a safe location for the operator to stand and work, a design whereby the operator""s hands and feet are safely away from moving parts, elimination of spinning chains, and a lockout to prevent operation of the lift cylinder when any tong is engaged.
Because of the great utility of prior art self-contained power tong units to makeup and breakout pipes, and the increasingly expanding market for such devices, it has been found highly desirable to make further improvements. It would be highly desirable to simplify the operation of such devices thereby reducing the number of components necessary for operation of the power tong unit. Consequently, there remains a need for an improved self-contained makeup and breakout unit that reduces the complexity and therefore the costs such as manufacturing costs and maintenance thereof. Those skilled in the art have long sought and will appreciate the present invention which addresses these and other problems.
The present invention was designed to provide more efficient operation to thereby reduce drilling costs, to improve reliability of making and breaking pipe joints, to permit increased automation to reduce required manpower, to improve safety, and to free other rig equipment for other uses.
Therefore, it is an object of the present invention to provide an improved self-contained power tong unit for making and breaking well bore tubulars.
Another object of the present invention is to provide a self-contained power tong with fewer and more reliable components.
An advantage of the present invention is increased reliability of operation.
Another advantage of the present invention is reduced costs.
Yet another advantage is improved reliability, accuracy, and consistency in making up joints.
These and other objectives, features, and advantages of the present invention will become apparent from the drawings, the descriptions given herein, and the appended claims. However, it will be understood that above-listed objectives and/or advantages of the invention are intended only as an aid in quickly understanding aspects of the invention, are not intended to limit the invention in anyway, and therefore do not form a comprehensive or restrictive list of objectives, and/or features, and/or advantages.
Accordingly, the invention comprises, in one embodiment thereof, a power tong system operable for making and breaking joints between wellbore tubulars. The power tong system may comprise one or more elements such as, for instance, a frame, a spinner secured to the frame that is operable for spinning the wellbore tubulars for the making and breaking of the joints, and/or a first member pivotally connected with respect to the frame such that the first member is rotatable with respect to the frame. The first member preferably defines a bore and/or a slot therein for receiving the wellbore tubulars. Other elements may, for instance, comprise a first plurality of gripping members mounted to the first member which are movable inwardly and outwardly for gripping and releasing the wellbore tubulars, and/or a piston/cylinder assembly comprising a piston slidable within a cylinder. The piston/cylinder assembly may be pivotally mounted with respect to the frame and with respect to the first member such that the first member is rotatable with respect to the frame in response to movement of the piston with respect to the cylinder. Additional elements may comprise a second member mounted to the frame also defining a slot therein for receiving the wellbore tubulars and a second plurality of gripping members mounted to the second member. The second plurality of gripping members may also be movable inwardly and outwardly for gripping and releasing the wellbore tubulars.
The power tong system may further comprise a control arm mounted to the first member, the control arm may be moveable between a first position and a second position, the first member may be rotatable for tightening the wellbore joints in the first position, the first member may be rotatable for loosening the wellbore joints in the second position. Other elements may comprise a fastener for selectively securing the control arm in the first position or the second position. In one embodiment, the fastener further comprises a pin, latch, or other fastening means.
The power tong system may further comprise a pivotal connection between the control arm and the first member and/or a pivotal connection between the control arm and the piston/cylinder assembly.
The plurality of gripping members may comprise a guide member whereby the guide member maybe moveable to a selectable position for a size of the wellbore tubulars. The guide member may then be affixed in the selectable position, and remain affixed, during gripping and releasing of the wellbore tubulars. The guide member cooperates with one or more gripping members that are radially moveable inwardly and outwardly for gripping and releasing the wellbore tubulars. The guide member maybe positioned along the bore through the first member for receiving the wellbore tubulars on an opposite side from the slot.
A method for a power tong system for making and breaking joints between wellbore tubulars are provided that may comprise one or more steps such as, for instance, mounting a plurality of gripping members to a rotatable member, providing that the gripping members are moveable inwardly toward the tubulars for gripping the wellbore tubulars and moveable outwardly away from the tubulars for releasing the wellbore tubulars, pivotally mounting a control to the rotatable member, connecting a piston/cylinder assembly which may comprise a piston and a cylinder, to the control arm such that the rotatable member rotates in response to movement of the piston with respect to the cylinder, providing that the control arm is moveable between a first position and a second position, providing that when the control arm is in the first position, then the member is operable for applying torque to the wellbore tubulars for making the joints, and/or providing that when the control arm is in the second position, then the member is operable for applying torque to the wellbore tubulars for breaking the joints.
The method may further comprise providing a frame, and pivotally mounting the rotatable member to the frame. The method may further comprise mounting a tubing inspection tool to the frame. The method may further comprise utilizing the tubing inspection tool for locating the joints with respect to the rotatable member.
The method may further comprise providing a second member, and providing that the second member is axially moveable with respect to the rotatable member and/or providing an extendable member operable for raising and lowering the rotatable member.
The method may further comprise providing an optical collar locator for locating the joints with respect to the first member and/or using optical circuits in the optical collar locator for inspecting the wellbore tubulars for nonconformities.
In yet another embodiment, the power tong system may comprise, a frame, a first member pivotally connected with respect to the frame such that the first member is rotatable with respect to the frame, a first gripping assembly mounted to the first member for gripping and releasing the wellbore tubulars, a second member mounted to the frame, a second gripping assembly mounted to the second member for gripping and releasing the wellbore tubulars, lift members attached to the frame for moving the first member and the second member upwardly and downwardly to align the first member and the second member with respect to the joints, a joint connection detector operable for detecting joint connector components for producing a joint signal to indicate the joint connection components wherein the joint connection detector may be in a clearance position with respect to the joint connection components, and an automatic control for receiving the joint connector. The automatic control may be operable for operating the lift members to automatically align the first gripping assembly and the second gripping assembly with respect to the joints.
The joint connection detector may further comprise a pipe inspection apparatus. For instance, an electrical coil, or other electrical device for receiving or sending electromagnetic signals, or for detecting magnetic flux changes, which may preferably be utilized by both the collar detector and the pipe inspection apparatus.
The joint connection detector may also comprise an optical recognition system. Moreover, the optical recognition system may be utilized for pipe inspection, assuming the pipe is clean and dry. Additional features such as automatically removable lens caps, covers, and so forth could also be utilized as desired to keep the lens clean. Moreover, infrared light or other wavelengths may be utilized to improve night vision and reduce effects of moisture or the like.
The system may further comprise automatic slips and a sender for the automatic slips that is used to send status information which may be received by the control. A plurality of sensors may be provided which are operable for measuring pressure, movement, and the like, and may be used, for instance, for determining torque versus turn during the making up of the joints. Other elements may comprise a piston/cylinder assembly which includes a piston slidable within a cylinder wherein the piston/cylinder assembly may be pivotally mounted with respect to the frame and/or a control arm mounted to first member. The piston/cylinder assembly may be pivotally connected to the control arm such that the first member is rotatable with respect to the frame in response to movement of the piston with respect to the cylinder.
This summary is not intended to be a limitation with respect to the features of the invention as claimed, and this and other objects can be more readily observed and understood in the detailed description of the preferred embodiment and in the claims.